The present invention relates to a packing machine, optionally an attachment for a packing machine, for packing bales of straw fodder of a "rectangular" form, wherein plastic sheeting is deposited in layers or overlapping around the straw fodder bale, the machine comprising two drive rollers which rotate the straw fodder bale around a substantially horizontal axis.
In agriculture, it is becoming more and more common to ensile straw fodder in the form of packed straw fodder bales. There is a movement away from the traditional silo plant. This method of ensilage, which has gradually become well known, has taken place in that the fodder, such as grass or straw, has been packed in round bales. Thereafter sheeting, preferably plastic sheeting, is wrapped around the bales, thus they can be stored outdoors without any problems, and the ensilage can take place inside a thus virtually hermetically packed bale. This has reduced the work connected with fodder considerably, and has also given rise to advantageous gains for the environment, as the leakage of silage fluids has virtually ceased and the use of chemicals has been greatly reduced.
Norwegian Patent 159366 makes known a packing machine (see FIG. 5) which packs straw fodder bales, often called round bales, which, broadly speaking, have in fact the form of a short cylinder. The round bale lies on two substantially parallel running rollers which are spaced apart from one another at a distance which is less than the diameter of the round bale. The rollers are operated rotationally and cause the bale to rotate around a substantially horizontal axis. The packing machine also has a superjacent crank mechanism which carries a vertically positioned roll of stretchable, adhesive plastic sheeting. The plastic sheeting is moved in a horizontal path around the fodder bale at the height of the center line of said fodder bale. When the drive rollers rotate the round bale around their horizontal axis at the same time as the crank mechanism moves the sheeting in said horizontal path, the plastic sheeting is wrapped in layers or overlapping around the round bale, and packs it almost hermetically. A packing machine of this kind can be stationary, per se, but in a practical embodiment which is already on the market, the packing machine is designed for rapid connection to a tractor, either mounted at the front or at the back. The power outlet of the tractor may be used for the whole of, or parts of, the operation .
Norwegian Patent 165536 makes known another kind of round bale packer which is mounted on an undercarriage on wheels. Here, too, the round bale is supported by two parallel running and spaced apart rollers which cause the round bale to rotate around a substantially horizontal axis. The rollers are positioned on a swivel table which can rotate in relation to the undercarriage in such a way that the round bale can also rotate around a substantially vertical axis. Fixed in a stationary manner to the undercarriage is a roll of plastic sheeting which, after being attached to the bale, is wrapped around said bale in layers or overlapping when the round bale is rotated around its two axes. Furthermore, the rollers can be tipped in relation to the undercarriage so that the round bale rolls off therefrom.
A similar round bale packer is also known from GB Application 2191984 and EP Application No. 0208034.
It has been established that in some countries equipment already exists which packs the straw fodder bales in an almost "rectangular" form. What is described by this term is a form which is almost parallelepiped and cube-shaped. The known packing machines referred to above are not capable of handling straw fodder bales of a rectangular form, only those of the conventional cylindrical form. There has been a need to be able to pack these rectangular straw fodder bales in a similar manner as the cylindrical bales.